Hi, Your history is suggestive of a condition called aphthous ulcers which cause a lots of pain. The exact cause is not known but the thoughts are about the loss of integrity of skin and mucus membrane which cause easy development of ulcers which normally heal within a few days although can recur anytime as your case before the healing of previous ulcers. There is no role of antibiotics. What you need is as follows: Consult a Doctor again and get a reference for an ENT or Oral Surgeon t get the exact diagnosis. It is advised to keep mouth and throat hygiene by drinking plenty of oral fluids, water in particular. Povidone iodine gargles. Take multivitamins, mineral and trace elements with Lycopene as this helps in early and better healing. Oral steroids and anti-inflammatory medicines help for pain relief and reduced inflammation. Get tests for blood vitamin levels, stool tests for possible colitis as one of the reasons and get treated is anything is found out. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, General Surgeon